Table levelling device

ABSTRACT

Articles are provided with hydraulic lines to supports where the supported length is proportional to the hydraulic liquid in the line. Control means may be set to interconnect all the lines or to disconnect the lines from each other.

mime States Patent 1 Ram [ 1 Oct. 30, 1973 TABLE LEVELLING DEVICEInventor: Alexander 0. Rain, Hamilton,

Ontario, Canada Filed: Oct. 21, 1970 Appl. No.: 82,691

U.S. Cl....... 248/1882, 248/1881 Int. Cl. F16!!! 11/24 Field of Search248/20, 188.2, 188.3;

References Cited UNITED STATES PATENTS 6/1920 l-Ieymann 92/44 X2,552,941 5/1951 Courtney 182/202 2,598,875 6/1952 Anderson 182/202 XFOREIGN PATENTS OR APPLICATIONS 834,501 3/1952 Germany 182/202 PrimaryExaminerWilliam I-I. Schultz Att0rneyWestell & Hanley [57] ABSTRACTArticles are provided with hydraulic lines to supports where thesupported length is proportional to the hydraulic liquid in the line.Control means may be set to interconnect all the lines or to disconnectthe lines from each other.

2 Claims, 5 Drawing Figures Patented Oct. 30, 1973 2 SheetsShe et 1 FIG.1

INVENTOR ALEXANDER O. BAIN Patented Oct. 30, 1973 2 Sheets-Sheet FIG. 5

INVENTOR ALEXANDER O. BAIN BY TABLE LEVELLING DEVICE This inventionrelates to a system for the support of articles supported or supportableon a plurality of spaced supports (such articles including but not beinglimited to furniture, appliances, industrial and laboratory equipment)to allow the adjustment of its attitude and to prevent the type ofvibration which takes place when the lower ends of the supports onfurniture or the like will not simultaneously contact the surface onwhich the furniture is supported (through such supports). It is notedthat the lastmentioned type of vibration may occur on a flat surfacewith supports of uneven length or with supports of even lengths on asurface of uneven contour. The invention is equally applicable to theprevention of vibration in either alternative situation and theinvention is applicable to the adjustment of attitude of a piece offurniture.

The invention will be described principally in relation to a piece offurniture having four supports. However, after consideration of thedescription of the invention, it will be obvious that the invention isequally applicable to furniture having three or five or more supports.

The invention provides, for example, an article of furniture, such as atable, having four supports which are designed and constructed to extendbetween the article and a supporting surface on which it is intendedthat the article shall rest. Each support is made longitudinallycontractable and extendable, and has, associated therewith, an hydraulicchamber whose volume enlarges and contracts as the length of the supportincreases and decreases, so that the supply of hydraulic fluid to thechamber tends to enlarge it and extend the support, and the weight ofthe table borne by the support tends to contract the support, contractthe chamber and drive liquid out of the latter. Conduits extend fromeach of the chambers and are connected thereto to convey liquid to andfrom the chambers. The conduits are also connectible to a control orvalving means which is designed either to connect them to each other orto disconnect them from each other. Liquid is used to fill the chambers,conduits and-relevant portions of the control or valving means.

A table fitted with supports in accord with the invention may be placedon the surface which is intended to support it, with the control orvalving means set so that the conduits are interconnected. With theweight of the table borne by the supports, the table will automaticallycome to rest with all supports contacting the surface on which the tablerests, since each support contacting the surface will tend to contractunder the weight it bears, tending to force liquid out of its associatedchamber, so that hydraulic pressure equalizes through the control means,with all supports contacting the support surface. lf the control meansis turned to disconnect the conduits at this point, the table willremain firmly seated on the support surface with all supports in contactwith the surface. It will be noted, in addition, that at the time thecontrol or valving means is set to interconnect the conduits, the tablemay be levelled-to the extent allowed by the range of movement of thesupports, in addition to having all the supports in contact. With thelevelling thus achieved to the degree permitted, the control or valvingmeans may be turned to the disconnect position. The table will beretained in its attitude while in the disconnect position since theamount of liquid in the conduit and chamber for each support is fixedduring disconnection of the conduits.

The table has been used as an example. However, it will be realized thatthe invention applies with equal utility and novelty to other articlesof furniture including: stands, desks, appliances (Such as washers andrefrigerators) industrial machinery, and any article ordinarily mountedon a floor or other base surface by legs, leg-like or spaced supports.The term leg supported article is intended to include all such devices.

The invention will be seen to be of particular advantage with sucharticles as: refrigerators, washers or dryers, or other articles, whichmay have to be set in locations where only one or two outside legs orsupports are exposed. To level or prevent vibration of such an articleby conventional means, with shims or the like, is a difficult andfrustrating operation. However, a refrigerator or other articleincorporating the invention, may be provided with a control knob for thecontrol or valving means with the control means located to be accessiblein the final position of the article. With the refrigerator in alocation where all sides but the side exposing the control or valvinglocation are inaccessible, the control or valve is turned tointerconnect the conduits so that all supports contact the floor. Whilemaintaining such contact, the refrigerator may be levelled to the extentallowed. If the control is now turned to disconnect the conduits, therefrigerator will now maintain its attitude.

With the refrigerator, as with other articles, it will be noted that theinvention allows all supports to be caused to bear on the floor or basesurface independently of whether or not the base or floor is planar. Inother words, within the range of the support movements, the system inaccord with the invention allows the support for the article to adapt toa surface of any contour, within the limits of expansion or contractionof the article.

The system has been described in relation to a four legged article.However it will be realized that the invention is of value with articleshaving three or more supports or legs.

The system has been described in relation to an article where four ormore legs or supports are all retractible and extendible. However, itwill be realized that some, although not all of the advantages of theinvention, accrue from the provision of furniture with some legs orsupports retractable and extendible and others fixed. Thus it will benoted that an article with only two or three legs or supports connectedin accord with the invention, may be adjusted so that all four legs orsupports contact a flat surface, and some irregularly contouredsurfaces. A similar statement may be made about an article with threelegs or supports having two connected in accord with the invention.

Such arrangements are not, however, as advantageous as the arrangementwhich provides all legs connected in accord with the invention. Thusalthough the device may be adjusted to have all legs in contact with thefloor, the weight may be unevenly distributed as compared to a devicewith all hydraulically connected legs, and moreover the device may belevel only to a much more limited degree.

In drawings which illustrate a preferred embodiment of the invention:

FIG. 1 shows a perspective of the device in accord with the invention;

FIG. 2 shows a support in accord with the invention;

FIG. 3 shows a control means partially broken away; and

FIGS. 3 and 5 are schematics showing the operation of the control means.

In FIG. 1 is shown a table having four supports or legs 10, each ofwhich is constructed in accord with FIG. 2. As shown the leg of FIG. 2the support comprises a downwardly extending tube or sleeve 12 having amember lid for contacting the floor supporting surface slidable therein.The member 14 is spaced from a plate 16 rigidly mounted in the tube 12by a bellows 18 designed to receive liquid and to expand in volume inresponse to the flow of liquid thereto and to contract in volume inresponse to the flow of liquid therefrom. (It will be noted that due tothe design of the bellows, the expansion and contraction are directlyrelated to the lengthening and shortening of the bellows to produceupward and downward sliding of the member 14 relative to the plate 16).The bellows 18 is connected for the conduction of liquid to a conduit20. Thus it will be seen that, in each support with the weight of thetable bearing downwardly thereon, that the support 10 will reach aposition determined by the amount fo liquid maintained in the bellowschamber under the pressure of the member 14 upwardly thereon. Thus anincrease in the supply of liquid tends to enlarge the bellows 18 andextend the support 10 while the reaction pressure of the base surface onthe member 14 tends to contract the bellows 18. As shown in FIG. 1, theconduits 20 are connected to a common control means being a valve havingfour ports 22 in a stationary member 24 one port corresponding to eachof the conduits 20 and an internal rotary member 25 having fourcorrespondingly radially directed and connected ports 23 turnable by themember and designed to assume two positions, the first of which is shownin FIG. 4 interconnecting the four conduits 20 and the second positionof which is shown in FIG. 5 where the conduits are disconnected. It willbe noted that these positions may be indicated to the user by indicia(not shown) on the stator or rotor, of the valve. The bellows 18,conduit 20 and valve means are filled with a liquid.

In accord with the invention, the table is adjusted to suit the contourof the floor surface on which it rests by turning the control means tothe position of FIG. 4, where all the conduits 20 are interconnected. Assoon as this is done the repsective bellows 18 will all contract orexpand to the extent necessary to move the liquid sufficiently toprovide through the interconnected hyraulie system (comprising thebellows, the conduits and the interconnecting valve) that all supportsare in contact with the floor. In addition, if desired, the attitude ofthe table may be varied leaving the supports in contact with thesurface, within the scope of movements of the retractable extendablesupports. When the desired attitude of the table has been achieved thecontrol means may be turned to the position of FIG. 5 so that all theconduits disconnected and the table will retain the attitude in which itis set since flow of liquid into and out of each chamber is prevented.

It will be obvious that the operation of the invention is independent ofthe number of supports or legs when all are connected and as to theoperation when fewer than all are connected, reference is made to thepreceding paragraph.

It will also be obvious that the invention is independent of the lengthof the supports or legs and although short legs are shown it will beobvious that longer legs or supports would work equally well in accordwith the invention.

It will further be obvious that the invention is independent of the typeof hydraulic chamber used and that, for example, a piston and cylindercould be used in substitution for the bellows, the only restriction onthe design of the hydraulic chamber is that the volume must be that thelength in the retraction and extension direction of the support must bedetermined by the volume of liquid in the hydraulic chamber so that anincrease in the amount of liquid in the chamber will extend the supportand contraction of the support will move liquid out of the chamber.

It will further be obvious that the type of control means for connectingand disconnecting the ports will not matter as long as the control meanshas two states, one state when all the conduits are connected in asingle hydraulic system and the other state where they are disconnectedinto separate hydraulic systems.

I claim:

1. Means for ensuring static support on a base surface of an article ofthe class comprising furniture, appliances, industrial and laboratoryequipment and which article is of the type which has four or more spacedindividual supports attached to the article and arranged to extenddownwardly therefrom to contact the base surface and support the articlethereabove;

at least all but one of said supports being longitudinally extendableand contractable in the downward extension direction to allow variationin the length thereof and constructed so that the length is increased bythe supply of liquid thereto and so that the decrease in length of saidsupport causes the expulsion of liquid therefrom,

a conduit corresponding to each of said contractable and extendablesupports mounted on said article for conducting liquid between a controlmeans and an expansible chamber in the corresponding support, each ofsaid conduits being connected to the expansible chamber of thecorresponding support to allow the supply of liquid to said support andto receive the liquid expelled therefrom,

said control means being arranged and constructed in one setting, tointerconnect said conduits and in another setting, to disconnect saidconduits from each other,

hydraulic liquid contained in said conduits and said control meanswhereby the contraction of one or more of said supports causes theextension of others of said supports, when said conduits areinterconnected.

2. Means as claimed in claim I wherein each of said supports islongitudinally contractable and extendable. =I

1. Means for ensuring static support on a base surface of an article ofthe class comprising furniture, appliances, industrial and laboratoryequipment and which article is of the type which has four or more spacedindividual supports attached to the article and arranged to extenddownwardly therefrom to contact the base surface and support the articlethereabove; at least all but one of said supports being longitudinallyextendable and contractable in the downward extension direction to allowvariation in the length thereof and constructed so that the length isincreased by the supply of liquid thereto and so that the decrease inlength of said support causes the expulsion of liquid therefrom, aconduit corresponding to each of said contractable and extendablesupports mounted on said article for conducting liquid between a controlmeans and an expansible chamber in the corresponding support, each ofsaid conduits being connected to the expansible chamber of thecorresponding support to allow the supply of liquid to said support andto receive the liquid expelled therefrom, said control means beingarranged and constructed in one setting, to interconnect said conduitsand in another setting, to disconnect said conduits from each other,hydraulic liquid contained in said conduits and said control meanswhereby the contraction of one or more of said supports causes theextension of others of said supports, when said conduits areinterconnected.
 2. Means as claimed in claim 1 wherein each of saidsupports is longitudinally contractable and extendable.